﻿using System;
using System.Collections.Generic;
using System.Text;

namespace RuoTeng.Util
{
    using System;
    using System.Data;
    using System.Configuration; 
    using System.Data.SqlClient;
    using System.Security.Cryptography;
    using System.IO;
    using System.Text;

    static  public class DES
    {
        //加解密密钥
        //private static string skey = "ruoteng8";
        //初始化向量
        private static byte[] DESIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };

        /// <summary>
        /// 加密
        /// </summary>
        #region DESEnCode DES加密
        public static string DESEnCode(string pToEncrypt, string sKey)
        {
           
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Encoding.GetEncoding("UTF-8").GetBytes(pToEncrypt);

            //建立加密对象的密钥和偏移量    
            //原文使用ASCIIEncoding.ASCII方法的GetBytes方法    
            //使得输入密码必须输入英文文本    
            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                ret.AppendFormat("{0:X2}", b);
            }
            ret.ToString();
            return ret.ToString();
        }
        #endregion
        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="pToDecrypt"> 待解密的字符串</param>
        /// <param name="sKey"> 解密密钥,要求为8字节,和加密密钥相同</param>
        /// <returns>解密成功返回解密后的字符串，失败返源串</returns>
        #region DESDeCode DES解密
        public static string DESDeCode(string pToDecrypt, string sKey)
        {            
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
            for (int x = 0; x < pToDecrypt.Length / 2; x++)
            {
                int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
                inputByteArray[x] = (byte)i;
            }

            des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
            des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();

            StringBuilder ret = new StringBuilder();
            return System.Text.Encoding.Default.GetString(ms.ToArray());           
        }
        #endregion
    }     
}
